Magnetorheological (MR) materials consist of dispersions of micrometer sized particulates of magnetically soft materials in organic liquids. When an external magnetic field is applied, the polarized magnetic particles form "pearl chains" constituting a fibrillated structure that exhibits a respectable "yield stress" (~ up to 100 kPa). MR fluids represent a technology enabling and intellectually engaging family of smart, field controllable materials. MR fluids can enable many technologies for active vibration control. Applications include shock absorbers, smart bridges, and dampers for high rise buildings for protection against seismic activity. The goal of the proposed program is to carefully investigate the application relevant, dynamic mechanical properties of MR materials with a view to elucidate the mechanics and also the mechanisms underlying MR materials. We will elucidate the transient stress response of MR fluids in switching magnetic fields. Our collaborations with industry will be useful in transferring our research outcomes to the industry.
